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| dc.contributor.author | Fufa, Bushen | |
| dc.date.accessioned | 2019-04-12T05:11:50Z | |
| dc.date.available | 2019-04-12T05:11:50Z | |
| dc.date.issued | 2019-04-12 | |
| dc.identifier.uri | http://hdl.handle.net/123456789/9446 | |
| dc.description.abstract | ABSTRACT The aim of this study was to generate baseline scientific information on some biological aspects and post-harvest loss of fishes of Beles and Gilgel Beles Rivers. Fish samples were collected monthly from September 2017 to July 2018 for eleven month using gillnets of various stretched mesh sizes and hooks and lines. Identification of fish was made to species level by comparing the sample characters with taxonomic keys found in literatures and specimens deposited. An index of relative importance (IRI) and Shannon diversity index (H´) were used to evaluate relative abundance and species diversity of fishes, respectively. A total of 1253 individual fishes belonging to 5 orders, 7 families, 9 genera and 11 species were caught in Beles and Gilgel Beles Rivers. Cyprinidae was best-represented family with the highest number of fish species while Labeo and Labeobarbus were the best represented genera in Beles and Gilgel Beles Rivers. A higher number of species were recorded in the Beles River (11 species) than in the Gilgel Beles River (5 species) during the study period. Labeobarbus nedgia, Labeo forskalii, Labeobarbus intermedius, Varicorhinus beso and Oreochromis niloticus were found in both rivers. The diversity index was higher in the Beles River (H´ = 2.85) than in the Gilgel Beles River (H´ = 1.13). Among sampling sites, diversity index was highest at Burge (H´ = 1.35) and lowest at Abrham Farm (H´ = 0.23). L. intermedius was the most abundant species with IRI values of (61.4%) and IRI (60.7%) both in Beles and Gilgel Beles Rivers, while L. forskalii was second (13.7%) in Beles River in total catch. L. intermedius, L. forskalii and L. nedgia in Beles and Gilgel Beles Rivers showed negative allometric growth as b value was less than 3. There were significant differences in the mean Fulton condition factor for L. forskalii in Beles River (ANOVA, P < 0.001) and for L. nedgia and L. intermedius in Gilgel Beles River (ANOVA, P < 0.05). Absolute fecundity of L. intermedius increased with an increase in fish size, and ranged from 2688 to 14509 with a mean of 6450 eggs. The post-harvest fish losses appraised in study area were spoilage, operational loss and size discrimination with estimated values of 16.9 kg due to spoilage, 5.4 kg due to operational loss, 2.3 kg due to size discrimination and 0.5 kg due to species preferences. In general, Beles River was higher than Gilgel Beles River, in terms of total numbers of fish caught and number of species recorded. Further long-term monitoring studies shall be undertaken to protect the dwindling fish stocks of Beles and Gilgel Beles Rivers. Key words: Beles, Biology, Gilgel Beles, post-harvest loss | en_US |
| dc.title | STUDIES ON SOME BIOLOGICAL ASPECTS AND POST-HARVEST LOSSES OF FISHES IN BELES AND GILGEL BELES RIVERS, BLUE NILE BASIN, ETHIOPIA | en_US |
| dc.type | Thesis | en_US |
